Many patients suffer from impaired coronary perfusion, i.e., an inadequate supply of blood, and therefore oxygen, to the heart. Counterpulsation devices increase the blood supply to the heart by increasing blood flow through the coronary arteries, the coronary arteries supplying blood to the heart.
PCT Publication WO 07/013,065 to Gross, which is incorporated herein by reference, describes apparatus, including a bifurcation stent comprising one or more electrodes, the stent configured to be placed in a primary passage and a secondary passage of a blood vessel, and a control unit, configured to drive the electrodes to apply a signal to a wall of the blood vessel, and to configure the signal to increase nitric oxide (NO) secretion by the wall.
In an embodiment described in the ′065 publication, a counterpulsation device is inserted in an ascending aorta of a subject. The counterpulsation device comprises one or more electrodes, and an implantable or external control unit. The control unit is described as being adapted to drive the electrodes to apply an electrical signal to a wall of the ascending aorta during systole, and to configure the signal to induce an increase in NO secretion by the wall. The increased NO secretion dilates the wall such that during systole the wall stores energy, and pressure on the heart is reduced. During diastole, the wall is described as constricting, releasing the stored energy and thereby increasing blood pressure and coronary blood flow. The control unit is described as being additionally configured to drive electrodes to apply, during diastole, stimulation configured to enhance the rapid constriction of aorta.
PCT Publication WO 07/113,818 to Cahan et al., which is incorporated herein by reference, describes an implantable artificial pacemaker (AAP) comprising oscillatory means providing pulsating signals at a pre-selected frequency, wherein the pacemaker is pacing the aorta. The application also describes an AAP further comprising: (i) a plurality of sensors disposed internally or externally to the aorta; and (ii) a pacing means in which the AAP stimulates the aortic media, augmenting physiological aortic elastic recoil. An AAP further comprising a processor capable of obtaining information from sensors and triggering an appropriate contraction wave in the aortic media is also described. A method of managing aortic rhythm is also described, comprising: (i) implanting an AAP comprising oscillatory means; and (ii) pulsating signals at a preselected frequency, so as to pace the aorta and in which the pulsating signals are provided by synchronizing and coordinating activation impulses in a portion of the aorta using electrical impulses.
US Patent Application Publication 2007/0150009 to Kveen et al., which is incorporated herein by reference, describes apparatus, systems, and methods that include a pacing apparatus having a stent electrode through which pulses of electrical current can be delivered. Stent electrodes are described as receiving energy for generating the electrical current from a variety of sources. Sources include one or more induction coils that can form at least a portion of the stent. Sources also include an implantable pulse generator coupled to a lead through which pulses of the electrical current are supplied to the stent electrodes.
U.S. Pat. No. 6,865,416 to Dev et al., which is incorporated herein by reference, describes methods for inducing or increasing the vasodilation of a vessel. The patent further provides methods for inducing or increasing the flow of fluid through a vessel. An electrical impulse is applied to the vessel in order to induce or increase vessel vasodilation or to induce or increase the flow of fluid through the vessel. The ′416 patent states:
“Although not wishing to be bound by any particular theory, the induction or increase of vessel vasodilation by an electrical impulse appears to result either from a direct effect caused by the electrical current applied to the vessel, or an indirect effect resulting from the release or stimulation of factors that promote vasodilation, such as the release of endothelium derived relaxation factors (EDRF) currently identified as nitric oxide (NO) or other vasodilating substances triggered by the electrical pulses applied to the cells of the vessel.”
US Patent Application Publication 2004/0106954 to Whitehurst et al., which is incorporated herein by reference, describes a treatment of congestive heart failure (CHF) that includes implantation of the discharge portion(s) of a catheter and, optionally, electrode(s) on a lead, near the tissue(s) to be stimulated. Stimulation pulses, i.e., drug infusion pulses and optional electrical pulses, are supplied by a stimulator implanted remotely, and through the catheter or lead, which is tunneled subcutaneously between the stimulator and stimulation site. Stimulation sites include the coronary arteries, the aorta, the left ventricle, the left atrium, and/or the pulmonary veins, among other locations. Disclosed treatments include drugs used for acute treatment of CHF, for chronic treatment of CHF, and drugs to reverse CHF. In an embodiment described in the ′954 publication, when catheters and/or electrodes of a stimulator are implanted, for example, in and/or near the left coronary artery or its branches, signals from an ECG sensor built into the stimulator are described as being used to adjust stimulation parameters.
US Patent Application Publication 2004/0054384 to Nachum, which is incorporated herein by reference, describes a treatment method and device for promoting a localized increase in the flow of blood through a blood vessel in an area of the body, the method including the steps of: (a) providing a system including: (i) at least a first electrode operatively contacting a first portion of body tissue; (ii) at least a second electrode operatively contacting a second portion of body tissue; and (iii) a signal generator, operatively connected to the first electrode and the second electrode, for providing a plurality of electrical impulses to the electrodes; (b) applying the electrical impulses so as to subject the muscular tissue to at least one voltage differential, thereby inducing repeated, contracting, directional movement of muscular tissue associated within the blood vessel, so as to produce a localized increase in the flow of blood through the blood vessel.
Sulzer IntraTherapeutics Inc. manufactures the IntraCoil® Self-Expanding Peripheral Stent (IntraCoil® Stent), which is described as a flexible coil-shaped metallic device that is used in the femoral and popliteal arteries in the leg to hold open areas that were blocked by atherosclerotic disease.
CardioMEMS, Inc., manufactures the EndoSure® Wireless AAA Pressure Measurement System, which is composed of two components: a miniaturized, wireless implantable sensor and an external electronics module. The external electronics module is described as wirelessly communicating with the sensors to deliver patient data. The wireless sensors are described as being powered by RF energy transmitted from an external electronics module and transmitting real-time data without batteries.
Cheetah Medical Inc. manufactures the Cheetah Reliant, which is described as providing continuous tracking of cardiac output and other parameters of cardiac function such as ventricular ejection time and heart rate.
The following patents and patent applications, which are incorporated herein by reference, may be of interest:
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